ON THE CLASSIFICATION OF THE ANIMAL KINGDOM. 199 



Naturee ' may doubtless be traced to tbis correspondence. Tbe 

 often voluminous descriptions, sometimes accompanied by draw- 

 ings, which form enclosures or parts of the letters in question, 

 have not been reproduced in the ' JSTaturhistorisk Tidsskrift,' as 

 not having sufficient value in proportion to the space they would 

 occupy. But as an instance of how the correspondence illustrates 

 the systematic works of Linnseus, we may mention the follow- 

 ing. In the second edition of ' Fauna Suecica ' we find under 

 the genus Hydra a species called triticea ; but in the twelfth 

 edition of tbe ' Systema Naturae ' this is omitted, and i-ightly 

 so. From one of the letters of Fabricius we gather in what 

 way Linnseus was led to correct the error ; for Fabricius here 

 communicates to him that a certain Schun (whose name is pro- 

 bably misspelt), minister at Bamf, had informed him that these 

 supposed Hydras, which occur frequently on the coast, were only 

 the ova of JBuccinum lapillus, L. This letter is written from 

 Edinburgh, 17 September, 1767 (Naturhistorisk Tidssrkrift, vii. 

 p. 459). 



But as I have already said, it is for the appreciation of Lin- 

 nseus's contemporaries and his influence on them (in short, of 

 the Linnsean period in natural history) that this correspondence 

 is principally valuable ; and 1 may perhaps, in conclusion, be per- 

 mitted to express a hope that some writer thoroughly qualified 

 for the task may be found inclined to work up in an exhaustive 

 manner the vast store of material for the history of science which 

 I feel sure must be contained in this remarkable collection of 

 letters. 



Copenhagen, April 1874. 



On the Classification of the Animal Kingdom. By T. H. Huxley 

 LL.D., Sec. R.S., F.L.S., &c. 



[Eead December 3rd, 1874.] 



In tbe twelfth edition of the * Systema Naturae ' Linnseus gives 

 the following definition of the object of classification : — 



" Methodus, anima scientise, indigitat primo intuitu, quodcunque 

 corpus naturale, ut hoc corpus dicat proprium suum nomen, et 

 hoc nomen qusecumque de nominate corpore beneficio seculi iuno- 

 tuere, ut sic in summa confusione rerum apparenti, summus con.- 

 spiciatur Naturae ordo " il. c. p. 13). 



